7.1.4 Sex Linkage

• What is the role of sex chromosomes in organisms?

  Determine sex
• What is the primary function of autosomes?

  Carry non-sex traits
• Match the type of sex-linked gene with its affected chromosome:

  X-linked ↔️ X chromosome

  Y-linked ↔️ Y chromosome
• Autosomes carry genes for sex-related traits.

  False
• Why are males more likely to express X-linked recessive traits?

  Only one X chromosome
• What is the genetic makeup of a female carrier of an X-linked recessive trait?

  One affected X, one healthy X
• What is an example of a Y-linked trait in humans?

  Testis determination
• Males are more likely to express X-linked recessive traits because they have only one X chromosome.

  True
• What chromosomes determine an organism's sex?

  Sex chromosomes
• Match the chromosome type with its definition:

  Sex Chromosomes ↔️ Determine sex

  Autosomes ↔️ Carry genes for non-sex traits
• Females can be carriers of X-linked traits if they inherit one affected X chromosome and one healthy X chromosome.


  True
• Describe the inheritance pattern of X-linked recessive traits in females.

  1️⃣ One affected X chromosome and one healthy X chromosome results in a carrier

  2️⃣ Two affected X chromosomes result in expression of the trait
• Males are more likely to express recessive X-linked traits because they have only one X chromosome.
• Match the location with the corresponding chromosome:

  X-linked genes ↔️ X chromosome

  Y-linked genes ↔️ Y chromosome
• Why is hemophilia more commonly expressed in males?

  They have one X chromosome
• In humans, females have two X chromosomes, while males have one X and one Y chromosome.
• Genes located on sex chromosomes are called sex-linked genes.


  True
• Why are Y-linked genes only expressed in males?

  Only males have a Y
• Sex-linked genes are located on the X or Y chromosomes.
• Order the steps in X-linked recessive trait inheritance in females:

  1️⃣ One affected X, one healthy X: Carrier

  2️⃣ Two affected X: Express trait
• X-linked traits affect both males and females, while Y-linked traits only affect males.


  True
• What chromosomes are X-linked genes located on?

  X chromosome
• Y-linked genes affect only males
• Females have two X chromosomes, while males have one X and one Y chromosome.


  True
• Sex-linked genes are located on the X or Y chromosome.
• What traits are associated with X-linked genes?

  Hemophilia, color blindness
• How are X-linked recessive traits expressed in males?

  If they inherit the affected X
• What is the only group affected by Y-linked genes?

  Males
• Sex-linked disorders typically result from genes on the X chromosome.


  True
• Y-linked disorders exclusively affect males because only males have a Y chromosome.